Metal-shears.



oli very UNITED. STATES PATENT orrion GEORGE Po'rsTADA, or 'SAN FeANcIsco, CALIFORNIA.

METAL-sneaks.

Specification of Letters Patent.

' Patented Nov. 9, 1909.

Application ledJanuary 2S, 1908. Serial No. 413,132.

To all whom 'itmay concern:

Be it known that I, 'GEORGE POTSTADA, a subject of the Emperor of Germany, residing at San Francisco, in the county ofSan Francisco and State of California, have invented a new and useful Metal-Shears, of

which the following isa specification in such full andclear terms as will enable thoseskilled' in the art to construct and usel the same.

This invention relates `to a shears used -for'the purpose ofvcutting metal and its object is to lighten such shears and at the same time make .the structuraljparts-thereof of such strength as to permit the shears tocut injuring the same.

Another object of the invention is to make the shears of sucha form as to securely hold the knife in a rigid position when it is passing through the metal in spite of the fact f that the cutting causes considerable side thrust on the blade of the knife.

Another object of the invention is to make a shear that will be capable of use as a bench shear, or' as a hand shear, means being provid on the bottom of the shear head to sec re the same in a vise, and the shearsA are also provided with a means whereby the handle may be placed, at different anglesffor different work. I It will also be possible to secure the shears 'to a bench by means of a special bracket, but this bracket does not form a part of the invention.

In the drawings in 'which the same numeral is applied to the same party throughout, Figure 1 is a sideeleva'tion of the shears, Fig. 2 is a plan View `of the shears, Fig. 3 is a side view of the head of the shears showing the side plate removed, Fig. 4 is a view of a 4modified yform of the means employed to `allow the knife pin to' move to push the knife down, Fig. 5 is a perspective view of the shear gbracket, and Fig. 6-.is across sectional View of the shear head.

The shear head 1 has the removable handle2 which is held in place by means of the screw 3, and the pivoted'handle 4 which operates the knife 5; The handle LLis jointed at 6 in order that the shear may be used in a number of dierent positions said handle 4 being held in its given position by means heavy metal without in any way of a yseries of radial notches in the short piece 7 of the handle 4, The head 1 has the jaw 8 projecting Qfrom its rear end the s ace between said jawand the main part o the head being such as to allow the maximum sheet of metal to be out to pass through between it and the plate 9 which secures the knife 5 in its proper place.

The knife 5 operates in a vertical channel inthe `knife head and it is held in the ver-v tical "psition by means of the plate 9 which is secured to the head by means of screws. In order that there may be no shearing stress on the screws holding the plate 9 in 9 near the corners thereof. The knife is moved bymeans of the pin 11 which passes through the eccentric head 12 which is a part of the handle piecel'l and eccentric operating in an eye in thehead and a similar eye in the plate 9. This head 12 has two parts, one bearing inthe plate 9 and the other bearing in the top part of the head 1, said parts belng spaced such a distance from each other as to allow the knife 5 to be in The in serted between them,'note Fig. 6. 11 is placed out of the center'of the hea 12 so that when the same is rotated the pin will have a motion with respect to the head in a direction substantially at right angles with the face of the jaw 8. Since the knife moves in a fixed channel and the pin moves in a circular path 'it is necessary to have somev play at the oint of connection of thepin and the kni e and this play may be given either by means of a slot in the knife 5, or

to give the full strength of the pin throughy the knife a small' eccentric 13 may be used to allow the pin to move the necessary amount, or a block 14 may be used to give the pin the necessary amount of 'lateral movement.

Since the material of the head is cast steel a tool steel knife 15 is let into the lower jaw and a similar toolsteel vknife 16 is let into the knife 5 to strengthen its edge. `When the shear is""nsed` with heavy metalyit is.

necessary to provide some means to prevent the same from being turned sidewise, since the knife will ycause'it to turn over when the cut is about to be made. This means side when a heavy sheet of metal is being' cut.

The knife head is provided with transverse ribs in order to strengthen the same, and it also has a depending rib 17 for the purpose of securing the shears in a vise when it is not wished to use both handles.

v If it is wished to provide a special bracket to hold the shears a sheet of metal may be pressed as shown in Fig. 5 and the rib 17 of the knife may be placed between the lips 18, 19 and 20 thereof, pins or small bolts be ing used to secure the shears to the bracket. The bracket is held in place on a bench or table by means of the feet 21 and 22 there being another foot on the corner opposite the lip 20, but which is not shown 1n the drawing. The plate from which this bracket is made may be corrugated as shown in order to make it stronger. The handle may be placed in the position shown in dotted lines in Fig. 1 if a knife having a reverse slant is used. 4

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is as, follows:

1. In a metal shear, a shear head having a knife channel and an eye, a plate secured to the head and having an eye opposite the eye in the knife head, a knife sliding between the plate and the head in the knife channel thereof, a double eccentric adapted to rotate in the eyes of the head and the plate, lugs carried by the head and adapted to prevent movement of the plate in the plane of the face of the head, a pin carried by the eccentric and adapted to move the knife when the.` eccentric is turned in the eyes of the plate and head, and a movable block surrounding the in and movable in the knife in a line parallel with the sheet of metal to be cut.

2. `In a metal shear, a shear head havin a knife channel and an eye, a plate secured lto the head and having an eye opposite the eye of the knife head, a knife sliding in the channel in the knife head, an eccentric having one part movablel in the eye of the late and another partmovable in thee e o the knife head said knife being carrie ybetween the two parts of the eccentric, andra pin passing through the eccentric and supporting the knife.

3. In a metalshear, a shear head having a knife channel and an eye near the top thereof, a plate secured to the head and having an eye opposite the eye of the knife head, lugs adapted to prevent the plate from moving in the plane of the knife, a knife movable in the knife channel ofthe head an eccentric having a part movable in the head of the shear and another part movable in the eye of the plate secured thereto, said knife extending up between the two parts of the eccentric, and a pin securing the knife to the eccentric and adapted to move the knife when the eccentric is moved.

4. In a` metal shear, a head having two eyes therein and a knife channel, an eccentric adapted to fit the eyes, and a knife carried between the parts of the eccentric bearing on each eye.

5. In a metal shear, a shear head having a knife channel and two eyes, an eccentric carried in the eyes, a knife carried by the eccentric and adapted to be moved thereby, a finger secured to one side vof the shear head and extending downwardly and outwardly from the saine and adapted to bea-r on a sheet of metal being cut, and means to operate the shear.

6. In a metal shear, a shear head having a channel for a knife and an eye in the top thereof, a plate secured to the side of the shear head and having an e e opposite the eye in the top of the head, a nife carried in the knife channel, an eccentric in the eyes and adapted to move the knife, means to secure the plate to the shear head, means to prevent the pressure of the cutting from injuring said securing means, and means to prevent the shear from turning when a thick plate of lmet-al is being cut.

7. In a metal shear, a shear head having l an` eye in the top thereof, a plate secured to the side of the head, a knife ada ted to slide between the plate and the hea means to move the knife, a lug carried by the shear head and adapted to bear on the plate being cut to prevent the shear from turning sidewise when a thick plate of metal is being cut, and a pocket for the insertion yof a handle in one end of the shear head.

8. In a metal shear, a shear head having a knife channel and an eye therein, a plate having a like eye therein immediately opposite the eye in the head, means to secure the plate to the head, lugs projecting from the head and adapted to prevent the stress on the plate from being transmitted to the late securing means, an eccentric having a bearing in each eye, and ay knife carried by the eccentric in the knife channel in the head.

'9. In a metal shear, a shear head having a knife channel and an eye therein, a late having an eye similar tothe eye in the ead and immediately opposite the same, means to secure the plate to the head, lugs project- [n 'testimcny whereol have set my hand y ing fromI the head and taking in notches in thls 21st day of January A. D. 1908, in the 10 the plate whereby the thrust on 'the plate is,y presenceof two subscribed witnesses.

prevented lfrom acting on the plate securing` GEORGE POTSTADA means, an eccentric having a; bearing in each of the eyes, a knife carried by the eccentric Witnesses: between its bearings, and means to turn said C. P. GRIFFIN, eccentric whereby thel knife is reciprocated. C. SANDERS. 

